著者

寺床 幸雄 梶田 真

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.125, no.4, pp.607-626, 2016

被引用文献数

2

---

 Minamata city is well known as the company town of Chisso Corporation, as the site of Minamata disease and, in recent times, as a city with environmentally friendly policies. The postwar experiences of Minamata city are often compared to a microcosm of Japanese modernization. A few decades earlier, the city faced and tackled several problems that most non-metropolitan cities currently face, such as an aging population and economic decline. There are meaningful lessons and suggestions we can adopt from Minamata city for sustainable development policies suited to non-metropolitan cities. This paper focuses on the economic history of Minamata (which includes not only Chisso but also other manufacturing companies and industries) and the dynamic relations between its local economy and politics. In Minamata, social tensions, such as those between the perpetrators and the victims of Minamata disease and between Chisso's labor and management, gradually disappeared due to reconciliation efforts and generational change. Minamata city office changed its vision of future development from being an industrial city to an environmentally friendly one, bearing in mind not only the experiences of Minamata disease victims but also the city's varied environmental resources. The residents of Minamata offered their support for these policies in recent mayor elections. Nevertheless, new problems began to emerge in the city. Jobs for the young had been limited for a long time, especially for men and those who were highly educated. One of the reasons for this is that Chisso prioritized retaining employees and restricted new hiring. Besides, the economic dominance of Chisso prevented local leaders and enterprises from growing. As a result, although Minamata's town planning, with its emphasis on environmentally friendly policies, received much attention and support, those policies could not be effectively implemented due to a lack of local human and institutional resources. Recently, however, young residents have begun to construct new social networks. It is worth noting that they share environmentally friendly visions. We can regard these kinds of movement as the results of continued efforts by Minamata city office and citizens. The economic and social dynamics of Minamata and the problems mentioned here are likely to be common to many non-metropolitan cities. Those cities must not be nearsighted about depopulation problems, but should investigate and try to maintain the conditions needed for long-term social and economic sustainability.

著者

大森 房吉

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.32, no.3, pp.116-124, 1920-03-15 (Released:2010-10-13)

著者

山本 純之 磯﨑 行雄

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.122, no.5, pp.791-806, 2013

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&emsp;Ever since the term stromatolith was first coined by Kalkowsky in 1908, research studies on stromatolites have continued for more than a century. This article reviews the study history of living and fossil stromatotelites. The history is divided into two parts by the discovery in 1961 by Logan of living stromatolites in Shark Bay, Western Australia, because this determined the subsequent main trend of studies on both living and fossil stromatolites. Major contributions during the last three decades include documentation of (1) a worldwide bloom of stromatolites in Proterozoic low-middle lateral shallow seas, and (2) oxygen-producing cyanobacterial activity related to stromatolites from the 1990s, resulting in various new aspects being clarified, which include <i>in-vitro</i> cultivation gradually revealing cyanobacterial calcification and dome-formation. Future studies will be directed towards reconciling morphological disparities and formation mechanisms among fossil, living, and cultured stromatolites.

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌

巻号頁・発行日

vol.17, no.11, pp.835, 1905

著者

寺床 幸雄 梶田 真

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.125, no.4, pp.607-626, 2016-08-25 (Released:2016-09-12)

参考文献数

21

被引用文献数

3 2

---

Minamata city is well known as the company town of Chisso Corporation, as the site of Minamata disease and, in recent times, as a city with environmentally friendly policies. The postwar experiences of Minamata city are often compared to a microcosm of Japanese modernization. A few decades earlier, the city faced and tackled several problems that most non-metropolitan cities currently face, such as an aging population and economic decline. There are meaningful lessons and suggestions we can adopt from Minamata city for sustainable development policies suited to non-metropolitan cities. This paper focuses on the economic history of Minamata (which includes not only Chisso but also other manufacturing companies and industries) and the dynamic relations between its local economy and politics. In Minamata, social tensions, such as those between the perpetrators and the victims of Minamata disease and between Chisso's labor and management, gradually disappeared due to reconciliation efforts and generational change. Minamata city office changed its vision of future development from being an industrial city to an environmentally friendly one, bearing in mind not only the experiences of Minamata disease victims but also the city's varied environmental resources. The residents of Minamata offered their support for these policies in recent mayor elections. Nevertheless, new problems began to emerge in the city. Jobs for the young had been limited for a long time, especially for men and those who were highly educated. One of the reasons for this is that Chisso prioritized retaining employees and restricted new hiring. Besides, the economic dominance of Chisso prevented local leaders and enterprises from growing. As a result, although Minamata's town planning, with its emphasis on environmentally friendly policies, received much attention and support, those policies could not be effectively implemented due to a lack of local human and institutional resources. Recently, however, young residents have begun to construct new social networks. It is worth noting that they share environmentally friendly visions. We can regard these kinds of movement as the results of continued efforts by Minamata city office and citizens. The economic and social dynamics of Minamata and the problems mentioned here are likely to be common to many non-metropolitan cities. Those cities must not be nearsighted about depopulation problems, but should investigate and try to maintain the conditions needed for long-term social and economic sustainability.

著者

片岡 龍峰

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.119, no.3, pp.519-526, 2010-06-25 (Released:2010-08-30)

参考文献数

16

被引用文献数

1 1

---

Possible influences of cosmic rays on terrestrial climate have been studied by many researchers since a good correlation between neutron monitor counts and global cloud amount was reported by Svensmark and Friis-Christensen in 1997. The cosmic ray-cloud relationship may be best tested during Forbush decrease events, in which cosmic rays largely decrease for several days associated with coronal mass ejections. Some cloud parameters are likely to respond to the transient decrease of cosmic rays with a typical time delay of several days, although we do not know the physics behind the cosmic-ray cloud relationship.

著者

早坂 一郎

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.38, no.2, pp.55-65_1, 1926-02-15 (Released:2010-10-13)

被引用文献数

2

著者

今岡 照喜 秋田 幸穂 永嶌 真理子

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.130, no.3, pp.369-378, 2021-06-25 (Released:2021-07-20)

参考文献数

34

被引用文献数

3

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愛媛県岩城島の白亜紀エジリンアルビタイトより稀なK–Zr珪酸塩鉱物であるデーリー石とLi–Na–Zr珪酸塩鉱物であるゼッツェル石が見いだされた。デーリー石とゼッツェル石のEPMA分析結果からそれぞれ(K1.93Ba0.01)Σ1.94(Zr0.99Hf0.02)Σ1.01Si5.98O15およびNa1.03(Zr0.96Hf0.02Y0.01Sc0.01)Σ1.00Li1.02(Si5.95Al0.04)Σ5.99O15の実験式が得られる。多孔質ジルコン,デーリー石,および不安定なジルコンを被覆するゼッツェル石の産状から,このアルビタイトは熱水活動時期におけるNa,K,Liに富んだ流体によるジルコニウム鉱物の分解と沈殿による交代反応の記録をよく保存している。これは日本列島におけるデーリー石とゼッツェル石産出の最初の報告である。

著者

松岡 憲知 池田 敦

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.121, no.2, pp.269-305, 2012-04-25 (Released:2012-05-29)

参考文献数

283

被引用文献数

6 4

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Periglacial process studies, which began in the mid-20th century, have greatly advanced in recent years following several breakthroughs. This paper reviews the latest breakthroughs supported by new technologies, themes, and international projects. New technologies have enabled small, high-resolution data loggers to monitor rock and soil movements, and thermal and hydrological properties in polar and alpine areas; enabled geophysical instruments to visualize two- and three- dimensional subsurface structures below periglacial features; and, enabled numerical simulations to predict future landform evolution. In particular, dramatic progress has been achieved in understanding bedrock shattering and falls, soil movements induced by freeze-thaw oscillations, controls on rock glacier creep, critical conditions for ice-wedge cracking, and biogeophysical impacts on non-sorted circles. Two key words, global warming and Mars, are appearing often in periglacial research. High mountains and polar lowlands face the fate of potential natural hazards associated with rock slides, debris flows and thermokarst subsidence, possibly originating from permafrost thawing. High-resolution orbital images and on-site explorations on Mars provide detailed information on small-scale, potential periglacial features, which are the morphologically equivalent of terrestrial counterparts. International collaboration is expected to further promote modeling various periglacial features on a global scale, improve the resolutions of periglacial climate indicators, and increase understanding of past and present Martian environments.

著者

高橋 成実 小平 秀一 佐藤 壮 山下 幹也 海宝 由佳 三浦 誠一 野 徹雄 瀧澤 薫 野口 直人 下村 典夫 金田 義行

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.124, no.5, pp.813-827, 2015-10-25 (Released:2015-11-04)

参考文献数

52

被引用文献数

6 8

---

Japan Agency for Marine-Earth Science and Technology carried out seismic surveys using ocean bottom seismographs (OBSs) and a multi-channel reflection survey system from 2004 to understand the structural characteristics and the continuity of the Izu–Ogasawara Arc crust. The Izu–Ogasawara Arc developed from the oceanic crust and produced andesitic middle crusts. The velocity is similar to that identified in the continental crust, and the initial continental crust might have been produced during development of the arc crust. To investigate the process of the Izu–Ogasawara Arc crust, many 2-D velocity structures are compared using unified specifications of data acquisition and analysis, and structural commonalities and differences are evaluated. The specification was confirmed previously through simulation studies using the structure obtained. These arc crustal structures have common characteristics, which are an upper crust with a Vp of 4.5–6.0 km/s, a middle crust with a Vp of 6.0–6.5 km/s, and a lower crust with a Vp of 6.5–7.5 km/s. The lower crust is composed of two layers; the upper part has a Vp of 6.5–6.8 km/s and the lower part has a Vp of 6.8–7.5 km/s. The uppermost mantle has a Vp of less than 8.0 km/s. Development of the arc crust results in crustal thickening accompanied by rifting. Back arc opening after rifting plays the role of crustal thinning. The Shikoku Basin, which is the older backarc basin, has a relatively thin crust with a thickness of approximately 10 km, and the eastern part has a high velocity lower crust with a Vp of over 7 km/s. In addition, the upper crust of the eastern part of the Shikoku Basin has some intrusive materials and strike slip faults with few vertical displacements. Such a high-velocity lower crust is not distributed in the Parece Vela basin. The Ogasawara Ridge has different characteristics from the above arc crust, which are a crustal thickness of approximately 20 km but a complicated structure including a narrow and thin crust in the N–S direction. Here, we introduce the structural characteristics of the entire Izu–Ogasawara Arc crusts based on unified seismic surveys and data analysis methods.

著者

町田 尚久

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.123, no.3, pp.363-377, 2014-06-25 (Released:2014-07-03)

参考文献数

31

被引用文献数

1

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To clarify the cause of heavy rains and weather related to a famous disaster that occurred in 1742, the weather sequence and its spatial distribution were investigated on the basis of local historical documents obtained from various areas of central Japan. As a result, the eastward movement of a typhoon was reconstructed in the sea off the south coast of central Japan. It was accompanied by an inflow of moist air around the eastern fringe of the typhoon, which brought about a rain zone extending from Kinki to Kanto from 27th Jul. to 1st Aug., according to the lunar calendar used at that time. The typhoon abruptly turned north when it reached southern Kanto and proceeded north across Honshu. It was accompanied by heavy rains and strong winds on 1st and 2nd Aug., which were recorded in central and western Kanto and areas further north. The abrupt change of direction seems to have been caused by a strong anticyclone that is thought to have extended to the east coast of Kanto. Although this situation around an anticyclone occurs frequently in late Summer, not enough evidence has been obtained yet on the situation at that time. The heavy rains and induced landslides caused floods particularly in the Ara, Tone, and Chikuma river basins. This is a matter of concern from the viewpoint of a fluvial geomorphic system analysis.

著者

山崎 直方

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.17, no.1, pp.5-20_2, 1905-01-15 (Released:2010-10-13)

著者

佐藤 昌人 八反地 剛 松岡 憲知

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.125, no.1, pp.133-153, 2016-02-25 (Released:2016-03-22)

参考文献数

168

被引用文献数

4 3

---

Weathering processes on Martian surface are among the essential issues for both understanding landform evolution and exploring water availability on Martian surface. Studies are reviewed on various weathering processes on Martian surface based on images, data collected by rovers, and laboratory approaches. Recent explorations by the Mars Exploration Rovers reveal that chemical weathering occurs on the surface of basaltic regolith. Dissolution of olivine and oxidation of Fe produces weathering rinds on basaltic surface regolith. Rock interiors also show vugs and veins filled with light-toned efflorescence indicative of chemical weathering. In particular, in high-latitude areas the two Viking landers and the Mars Pathfinder observed honeycomb weathering, angular rock fragments, and polygonal cracks in bedrock. Most of these features are also observed in the Antarctica and other cold deserts on Earth, and are generally attributed to physical weathering such as salt crystallization, thermal weathering, and/or frost weathering. Some studies successfully estimate periods and rates of weathering on the Martian surface, which promote a further understanding of environmental changes and landform evolution.

著者

金田 楢太郎

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.4, no.2, pp.78-81, 1892-02-25 (Released:2010-10-13)

著者

田林 雄 山室 真澄

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.121, no.3, pp.411-420, 2012-06-25 (Released:2012-07-09)

参考文献数

40

被引用文献数

4

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Nitrogen compound deposition as a result of human activities on the terrestrial surface has increased sharply during the last one hundred years, causing ecological problems. One problem is nitrogen saturation in forest ecosystems, which results in the forest ecosystem receiving more nitrogen than required. In recent years, nitrogen oxide emissions have been decreasing in Japan; however, the total deposition of nitrogen is not decreasing because of cross-boundary emissions from other countries. As depositions in forest ecosystems increase, the likelihood of nitrogen saturation increases. At the same time, certain species of trees, geological conditions, and climate will affect nitrogen saturation. In Japan, there is heavy precipitation in summer; therefore, decreases in nitrate concentrations of stream water cannot be observed. Stable isotope analysis is the key to elucidating nitrogen dynamics between the atmosphere and rivers. From the atmosphere to stream water, nitrogen compounds have many chemical and biological reactions. Because a stable isotope is an indicator of the progress of these reactions, frequent analyses of stable isotope compositions reveals how nitrogen moves from the atmosphere to stream water.

著者

鈴木 富之

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.120, no.3, pp.466-485, 2011-06-25 (Released:2011-09-06)

参考文献数

42

被引用文献数

2 5

---

Many business travelers often stay in large cities because of the concentration of various urban functions. The number of foreign tourists visiting Japan has increased in recent years. The main destinations are metropolitan areas such as Tokyo and Osaka. Given this situation, it is necessary to develop cheaper accommodations for foreign and business travellers who want to stay in those areas for long periods. The purpose of this study is to examine the characteristics and factors behind the evolution of accommodations in the Sanya district, which is located in an “inner-city” in Tokyo. Cheap lodging houses in Sanya have been in decline since the collapse of Japan's asset inflation-led economic bubble in the early 1990s. Managers of accommodations started to accept foreign and business guests. These accommodations have attempted to differentiate themselves from hotels located in central Tokyo in terms of service and lower tariffs. The following three reasons, which this study clarifies, help explain why accommodations in the Sanya district have evolved. First, Sanya was traditionally developed as a “Yoseba”, a place in which day laborers lived. In addition, Sanya is located close to central Tokyo. Secondly, due to a decreasing number of day laborers, cheap lodging houses had empty rooms. Therefore, their managers started to accept foreign tourists and business travellers. In addition, various mass media started to report favorably on Sanya during the World Cup Football games in 2002, although the Sanya district previously had a negative image. Lastly, many foreign tourists began to stay in the area after the World Cup.

著者

楮原 京子 田代 佑徳 小坂 英輝 阿部 恒平 中山 英二 三輪 敦志 今泉 俊文

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.125, no.2, pp.221-241, 2016-04-25 (Released:2016-05-12)

参考文献数

47

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We should understand the earthquake potential in and around Quaternary fault zones, in view of recent destructive inland earthquakes at previously unknown active fault zones in Japan. The Senpoku Plain and its surrounding areas are characterized by high seismic activity in northeast Japan, highlighted by four destructive earthquakes, M 6.8 in 2008, M 6.4 in 2003, M 6.5 in 1962, and M 7.0 in 1900, which occurred during the past 100 years, although few geomorphic features indicate active faulting. A comprehensive survey was conducted on the tectonic geomorphology in the area to understand the structural and geomorphic expression of the Ichinoseki–Ishikoshi Flexure Line (IIFL), which suggests Quaternary activity. Geological and geomorphical mapping shows that the IIFL is located between the Kitakami Lowland Fault Zone and the Senpoku Plain. The IIFL extends about 30 km from Isawa to Ishikoshi with a slightly sinuous trace. A high-resolution seismic reflection profile and a gravity profile define the subsurface geometry of the IIFL. The IIFL is interpreted to be a steeply west-dipping reverse fault. The Pliocene Kazawa and Yushima Formations typically dip 40° to 20°E along the IIFL, and are overlain by the Pleistocene Mataki Formation, which becomes thinner toward the fold axis of the IIFL, and their dips decrease progressively upward. This suggests that the Mataki Formation was deposited concurrently with fault activity of the IIFL. Fission-track dating of a tuff layer within the uppermost section of the Kazawa Formation indicates that active reverse faulting of the IIFL began at about 2 Ma. At least 280 m of the tectonic uplift is consumed by active faulting and the average uplift rates are estimated to be 0.14–0.08 mm/yr. Vertical separations of Hh surface are about 15 to 40 m. Heights of fold scarps on L1 surface are about 2 m. Their ages are determined to be 0.4–0.5 Ma for Hh and 24–12 ka for L1, respectively. Therefore, the Quaternary average uplift rates of the IIFL are estimated to be 0.03–0.17 mm/yr. Quaternary activity of the IIFL is weak, but there are differences in the magnitude of dissection in the Iwai Hills between the hanging-wall and the footwall of the IIFL.

著者

坪井 九馬三 神保 小虎 箕作 元八 野口 保興 磯田 良 山崎 直方

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.14, no.12, pp.a1-a46, 1902-12-15 (Released:2010-10-13)

出版者

公益社団法人 東京地学協会

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.125, no.2, pp.Cover02_01-Cover02_02, 2016

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&emsp;かつて超大陸パンゲア西部の陸棚浅海や砂丘で堆積した古生代の地層がほぼ水平なまま隆起し,標高2,000 mの台地表面を飾っていることは驚きだ.隆起以前から存在したコロラド川は,大地の上昇に抗って,もともとの川筋を残したまま穿入蛇行を続けて,現在もV字谷を削っている.北米大陸直下にあるマントル上部の上昇流が急速隆起の原動力だが,この隆起が止まれば大峡谷の崖はすぐに浸食されはじめ,ただのつまらない緩斜面に急速に変わってしまうだろう.単独の急崖で多様な地質時代の地層を一目で見ることができるのは大きな魅力であるが,あの急な崖をつくる地層そのものが特異なわけでない.同じ地層がほとんど変形もせず延々と周辺地域の地下につながっているからである.<br>&emsp;日本人がグランドキャニオンを訪れる場合,米国西海岸南部からインターステーツ40号線(旧ルート66号線)を東に進み,途中で北に折れて,大峡谷の南側に出るコースが定番であろう.Mather Point展望台やBright Angel Trailheadに自動車横づけで,台地上からのあの絶景を眺めることができる.しかし,あえて崖沿いにさらに東に小一時間進むと,大峡谷東部のコロラド川上流部では谷幅が広がり,台地の上からも蛇行する川の流れが見える.夕闇迫る頃のDesert View展望台から,ちょっと趣の異なる光景を楽しむことができた.さらに,よく目をこらすと,水平な古生層最下部のカンブリア系と,その下の先カンブリア時代の岩石との間の明瞭な不整合(the Great Unconformityと呼ばれる)を目視できる.<br>(写真と説明:磯﨑行雄)

著者

岩森 光 行竹 洋平 飯尾 能久 中村 仁美

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.128, no.5, pp.761-783, 2019-10-25 (Released:2019-11-15)

参考文献数

116

被引用文献数

2 3

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A total of one to ten ocean masses of water (including H2O, OH, H in gas, liquid, and solid phases) is probably stored in the Earth's crust-mantle system as a variety of forms and components. Of these, the liquid phase involves aqueous solution, hydrous melt, and supercritical fluid, which may change composition continuously from a diluted aqueous fluid to a silicate melt above the second critical endpoint. These fluids are termed “geofluids” in this review paper, which describes physicochemical conditions required for the presence of geofluids, their compositions, and related tectonic setting and geodynamic phenomena. On the basis of the maximum water content that can be stored in crust-mantle rocks, subduction zone processes are discussed in which slab-derived fluids that are enriched in solid components play important roles: viscosity-flow-thermal field and melting in the mantle wedge, and origin of deep-seated fluid such as Arima-type brine. The fluid flux in the arc crust may be captured by geophysical and geochemical observations, such as seismicity, seismic velocity, electrical conductivity, and helium isotopic ratios. Several specific phenomena such as migrating seismic events and localized crustal deformation may be attributed to such fluid fluxes from the depths, which have been induced by an elevated fluid pressure and a reduction of rock strength and viscosity.